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      <title>Redis搭建读写分离 - 交互式测验</title>
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    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>Redis搭建读写分离 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
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                    <div id="question-container">
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                    <div id="hint-container" class="hint-container"></div>
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                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
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                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "根据文档，Redis哨兵模式（Sentinel Mode）最核心的作用是什么？",
    "options": [
      "在多个从服务器之间进行读取请求的负载均衡。",
      "将数据分片存储在不同的Redis实例中，以支持海量数据。",
      "作为一种容灾方案，在主服务器不可用时自动进行故障转移，选举新的主服务器。",
      "仅用于备份主服务器的数据到从服务器。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档明确指出哨兵机制是一种容灾方案，其核心功能是监控主数据库的健康状况，并在主数据库出现故障时，自动将一个从数据库提升为新的主数据库，从而保证系统的高可用性。负载均衡和数据分片是其他集群技术的功能，而数据备份是主从复制本身的功能。",
    "source": "文档中「1.4 哨兵模式」部分",
    "hint": "文档中提到：\"一旦哨兵发现主服务器不可用时，就找到一个合适的从服务器成为主服务器。\""
  },
  {
    "question": "在Redis主从复制的生命周期中，什么情况下通常会触发“全量复制”？",
    "options": [
      "当主服务器的数据发生少量变更时。",
      "在从服务器（Slave）初始化阶段，首次与主服务器（Master）建立连接时。",
      "当客户端向从服务器发送写命令时。",
      "当网络发生短暂中断后立即恢复时。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档中提到，“Redis全量复制一般发生在Slave初始化阶段，这时Slave需要将Master上的所有数据都复制一份。” 这是为了确保从服务器在开始接收增量更新之前，拥有一个与主服务器完全一致的基础数据集。少量数据变更会触发增量复制。",
    "source": "文档中「1.2.3 全量复制」部分",
    "hint": "思考一下，从服务器在刚加入集群时，是如何获得第一份完整数据的？"
  },
  {
    "question": "文档中强调，实施“读写分离”架构主要是为了解决什么问题？",
    "options": [
      "保证主从数据库之间的数据绝对一致性。",
      "实现数据库的自动故障转移。",
      "解决数据库的写性能瓶颈。",
      "解决数据库的读性能瓶颈，特别是在“读多写少”的业务场景下。"
    ],
    "correctAnswerIndex": 3,
    "explanation": "文档明确概括：“用一句话概括，读写分离是用来解决数据库的读性能瓶颈的。” 它通过将耗时的读请求分散到从服务器，极大地减轻了主服务器的压力，从而提升了整个集群的读取能力和响应速度。自动故障转移是哨兵模式的功能。",
    "source": "文档中「1.5 为什么要使用主从复制和读写操作呢？」部分",
    "hint": "文档提到：\"大多数互联网业务，往往读多写少，这时候，数据库的读会首先成为数据库的瓶颈...\""
  },
  {
    "question": "在全量复制过程中，当主服务器（Master）接收到`SYNC`命令后，它在后台生成RDB快照文件的同时，会如何处理新接收到的写命令？",
    "options": [
      "拒绝所有新的写命令，直到全量复制完成。",
      "立即将这些写命令发送给从服务器。",
      "使用缓冲区记录所有新的写命令，待RDB文件发送完毕后再同步给从服务器。",
      "直接将这些新的写命令追加到正在生成的RDB文件中。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档在全量复制的步骤中描述：“主服务器接收到SYNC命名后，开始执行BGSAVE命令生成RDB文件并使用缓冲区记录此后执行的所有写命令”。这个机制确保了在快照生成和传输期间的数据变更不会丢失，保证了数据最终的一致性。",
    "source": "文档中「1.2.3 全量复制」部分",
    "hint": "在从节点加载RDB文件期间，是无法处理新命令的。主节点必须有一种方式来'暂存'这个时间段内的变更。"
  },
  {
    "question": "根据文档，主从复制（Master-Slave Replication）机制除了可以分担读压力外，另一个至关重要的作用是什么？",
    "options": [
      "作为一种数据备份方案，避免因单点故障（如主库硬盘损坏）导致数据丢失。",
      "显著提高数据库的写入性能。",
      "自动在主从节点之间进行数据校验和修复。",
      "实现跨数据中心的负载均衡。"
    ],
    "correctAnswerIndex": 0,
    "explanation": "文档在开篇就定义了主从复制：“主从复制是一种数据备份的方案”，并举例说明“如果通过redis的主从复制机制就可以避免这种单点故障”。这是其在保障数据安全和高可用性方面最基本、最重要的作用。",
    "source": "文档中「1.2.1 基本概念」和「1.5 为什么要使用主从复制和读写操作呢？」部分",
    "hint": "文档中对主从复制的第一个定义句就揭示了答案。"
  },
  {
    "question": "在手动配置Redis主从复制时，需要在从服务器（Slave）的配置文件中添加哪项最关键的信息来指定其主节点？",
    "options": [
      "哨兵（Sentinel）服务器的IP地址和端口号。",
      "集群中所有其他从服务器的IP地址列表。",
      "主服务器（Master）的IP地址和端口号。",
      "从服务器自身的公网IP地址和认证密码。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档在“1.6 配置主从复制”一节中明确指出：“Master需要把自己的数据同步到两个slave中，所以要在两个slave中配置master的ip和端口号。” 这是从服务器能够找到并连接到主服务器以开始复制过程的先决条件。",
    "source": "文档中「1.6 配置主从复制」部分",
    "hint": "思考一下，作为“追随者”（从节点），它首先需要知道要“追随”谁（主节点）。"
  },
  {
    "question": "文档描述了Redis主从复制的两种核心同步方式，它们分别是什么？",
    "options": [
      "同步复制和异步复制",
      "单向复制和双向复制",
      "全量复制和增量复制",
      "快照复制和日志复制"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档在“1.2.2 主要分为6个步骤”一节中明确指出，首次建立复制是“全量复制”的方式，而后续主节点发生数据变更时，则采用“增量复制”。这两者共同构成了Redis主从复制的数据同步机制。",
    "source": "文档中「1.2.2 主要分为6个步骤」部分",
    "hint": "文档提到了两种复制场景：首次建立连接时和后续数据变更时，分别对应了不同的复制方式。"
  }
];
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            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
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            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

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                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
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                '<div class="score-card">' +
                '<h3>错误率</h3>' +
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                '<div class="score-card score-details">' +
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                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
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                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  